I can also recommend the 29A magazine and z0mbie's website - http://z0mbie.host.sk/.

I still have the "Little Black book of computer viruses". I just got my first AT computer then (a 486DX). Very entertaining stuff that was...

http://home.swipnet.se/smaffy/asm/info/vir.pdf

I was as a 15-year-old briefly involved with Phalcon/Skism, the group that produced 40Hex. I also wrote a couple of ASM DOS viruses. They weren't intended to destroy anything, just sort of adolescent graffiti in x86 machine code form.

I only have a bit of code left from that period, some of which is here:

http://adam.ierymenko.name/ye_olde_source_code.html

No viruses, but some IRC hacks I wrote around the same time.